Facebook is nearing completion on Building 2 at its Prineville data center.

In most data centers, the two primary contributors to cooling energy use are the refrigeration chiller, which accounts for approximately 50 percent of cooling systems, and the Computer Room Air Conditioning units, which account for approximately 33 percent. By using the evaporative cooling, Facebook uses 70 percent less water than conventional cooling systems.

In addition to the near completion of Building 2, Facebook is building a smaller data center for “cold storage” east of Building 2.

“It’s actually Building 4, coming before Building 3,” said Senior Planner for the City of Prineville Joshua Smith. “It’s a smaller building, up behind the second building.”